|Posted by Devinder Kumar Dhiman on February 25, 2015 at 1:45 AM|
When we talk about cosmology, we hear that the space is expanding which is causing all stars and galaxies to recede from each other. It is also claimed in Inflation theory that space expanded exponentially in the first fraction of a second after Big Bang. So, all cosmologists agree that space is expanding.
But, what is there inside space that is expanding? Take a simple example, if you have a piece of rubber in your hand, you can stretch it, but if your don't have a rubber in your hands and simply make an action of stretching, how can you say that you have stretched the rubber. Similarly for talking about expansion of space, space has to have something inside it that can expand.
On one hand, it is generally agreed that space expands and on the other, it is believed that there is nothing inside the space that can expand. Then how to explain this paradox.
To get out of this dilemma, fourth dimension of time is added to three dimensions of space, and it is said that space-time fabric is expanding. Space-time fabric also gets curved by gravity. Wherever there is high gravity, space-time fabric is highly curved.
Now, we come back to our simple experiment again. Let the stretched rubber in our hands has a small weight kept on it, it will curve downwards. Higher the mass of the object, sharper the curve will be. This is in accordance with space-time fabric theory, where the curve is increased proportional to the mass of the object lying on space-time fabric.
If there is no rubber in your hands and there is no weight lying on the rubber, can you still say that the rubber is curved? No, you cannot. So, there has to be something physically present that can curve by the weight kept on it. It explains that space-time fabric has to be something physical which can curve around heavy mass.
If space-time fabric is something physical that can curve by the presence of heavy mass, then it is wrong to say that space does not have any medium that can expand.
So. we should follow one rule, either the space is expanding, or nothing exists in space that can expand, not both.
If we agree on expansion of space, then we must also agree that there is something physical in space, that expands.